Apple is preparing a significant expansion of its iPhone sales capabilities in its official retail stores, according to sources. Late in August, many Apple Stores in the United States will kick off a pilot program for customers to be able to purchase a new iPhone via the latest carrier upgrade programs: AT&T Next, T-Mobile JUMP, and Verizon Edge. Currently, iPhones bought at Apple Stores must either be purchased on a two-year deal, or at full-price (unlocked) with no contract…

AT&T Next allows customers to upgrade to a new phone every 12 or 18 months with no down payment upgrade fee, activation, or financing fee. The price of the phone is rolled into the monthly service bill. T-Mobile JUMP allows customers to upgrade to a new smartphone at their leisure, and the price of the phone is also packed into the monthly phone bill. Verizon EDGE is similar is similar to the T-Mobile and AT&T programs, and it allows the price of the phone to be paid off over the course of 20 months. Sprint also has a similar One Up program, but sources did not have any information on Apple supporting those (yet).

Apple Stores will be training extensively for this new program between August 10th and August 28th, we reported yesterday. We also noted that Apple is working on improvements to Genius Bar customer service. This iPhone sales expansion will mark the second improvement in recent months. In June, Apple began allowing iPhones to be purchased through its stores on month-to-month and pre-paid plans. It is possible that Apple decides not to go through with the pilot testing as yet-to-be-launched initiatives can always be cancelled late in development. We’ve reached out to Apple, Verizon Wireless, T-Mobile, and AT&T for comment on this story, and we’ll update if we hear back from any of those companies.